Hey guys. I seem to have a problem with 4870 512mb crossfire.
Both GPUs are only used when I run 3DMARK06 pixel shader tests, but only one gets used by games like L4D and Crysis while the other sits there and do nothing.

I've played around with CCC, and there is no luck.
The cards are Palit Sonic Dual edition and Sapphire. Wondering if anyone can help me with this
Thanks!

Your best bet would probably be in the ATI x-fire forums. Crysis hates x-fire as I'm sure you've heard, but as for left 4 dead Im not so sure. But it seems like if your cards are working in 3dmark they should work if supported in games too...

I had a similar problem in Crysis and FC2 and found that toggling the crossfire off/then on in CCC just before loading the game fixed it. Once you close the game, though, it gos back to one card so youll need to do it again.